JPH06221264A - Reciprocation type compressor - Google Patents

Abstract

PURPOSE:To surely maintain the sufficient volumetric efficiency even in the case where a rotary valve is rotated at a high speed. CONSTITUTION:Continuity passages 2A-2F are formed between each bore 1A-1F and a center axis hole 1a. A rotary valve 22 connected to a driving shaft is equipped with a suction passage 25 and a residual gas bypass groove 28. The residual gas bypass groove 28 consists of a high pressure side groove 28a communicated with the continuity passage 2C of the bore 1C at the time of finishing discharge, and a low pressure side groove 28b communicated with the continuity passage 2A of the bore 1B during the compression stroke synchronously with the groove 28a, and a communicating groove 28c for connecting these high pressure side groove 28a and the low pressure side groove 28b. In the low pressure side groove 28b, a branch passage 28d to be connected to the continuity passage 2A of the bore 1A immediately after finishing the suction stroke by the rotation of the rotary valve 22 is extended. Even in the case where the speed of rotation of the rotary valve 22 is increased, the gas inside of the residual gas bypass groove 28 is discharge in two stages to the bore 1B during the compression stroke and the bore 1A immediately after finishing the suction stroke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a reciprocating compressor suitable for air conditioning of vehicles.

[0002]

2. Description of the Related Art Conventionally, each piston reciprocates in a plurality of bores formed in a cylinder block in parallel with a drive shaft, such as a swash plate compressor disclosed in Japanese Patent Laid-Open No. 59-145378. A compressor that compresses a refrigerant gas is known. In this type of compressor, a drive shaft is inserted into and supported by a central shaft hole of a cylinder block, and each piston is linearly moved in each bore by being linked to a swash plate in a crank chamber that cooperates with the drive shaft. A housing is joined to the end surface of the cylinder block via a valve plate, and a suction chamber for supplying the refrigerant gas into the bore and a discharge chamber for discharging the refrigerant gas compressed by the piston in the bore are provided in the housing. Has been formed. The suction of the refrigerant gas from the suction chamber into the bore is performed by moving the piston to the bottom dead center position, and the suction port formed in the valve plate and the pressure inside the bore provided on the bore side of the suction port. And an intake valve that opens the intake port accordingly. Further, the discharge of the refrigerant gas from the inside of the bore to the discharge chamber is performed by moving the piston to the top dead center position, and the discharge port formed on the valve plate and the discharge chamber side of this discharge port are provided inside the bore. And a discharge valve that opens the discharge port in response to pressure.

[0003]

However, in the conventional compressor, since the suction valve is constructed so as to overcome the elastic force of its own acting in the direction of maintaining the closed state to open the valve, the pressure loss is reduced. Is big. Further, in the conventional compressor, high-pressure refrigerant gas remains in the bore immediately after the end of discharge, that is, in the slight gap between the piston and the valve plate that has reached the top dead center position or in the discharge port of the valve plate. This residual gas re-expands with the movement of the piston to the bottom dead center position, resulting in a decrease in the amount of suction into the bore. These pressure loss and reduction of the suction amount into the bore lead to deterioration of volume efficiency.

Therefore, the present applicant has filed Japanese Patent Application No. 3-2291.
No. 66 proposed a reciprocating compressor with excellent volume efficiency. In this compressor, a conduction path that radially communicates each bore and the central shaft hole is formed, and a rotary valve is coupled to the drive shaft so as to be synchronously rotatable. The rotary valve is formed with an intake passage that sequentially connects the passage of each bore in the intake stroke and the intake chamber, and residual gas that bypasses residual gas from the bore at the end of discharge to the low pressure side bore. A bypass passage is formed. As the residual gas bypass passage, a residual gas bypass hole and a residual gas bypass groove are disclosed. The residual gas bypass hole and the residual gas bypass groove are
It is composed of a high-pressure side opening communicating with the conduction path of the bore at the end of discharge, a low-pressure side opening communicating with the conduction path of the low-pressure side bore, and a communication path connecting these high-pressure side opening and low-pressure side opening.

In the proposed compressor, the rotary valve rotates in synchronization with the drive shaft, so that the refrigerant gas in the suction chamber is sequentially sucked into each bore, and the suction operation of the refrigerant gas is smooth and stable in each bore. As a result, the pressure loss is extremely reduced. In addition, by rotating the rotary valve in synchronization with the drive shaft, residual gas is bypassed from the bore at the end of discharge to the low pressure side bore, and re-expansion of residual gas during the suction stroke of the bore is small, The refrigerant gas in the suction chamber is surely sucked. Thus, high volumetric efficiency can be maintained with this compressor.

However, in this compressor, since the low-pressure side opening is angled so as to communicate with the passage of the single bore, the rotation speed of the drive shaft and the rotary valve increases, so that the low-pressure side opening communicates. If the time becomes short, the residual gas recovered at the high pressure side opening will not be sufficiently discharged at the low pressure side opening. Therefore, in this case, gas remains in the residual gas bypass passage to cause bypass shortage, and poor volumetric efficiency due to poor suction efficiency.

An object of the present invention is to reliably maintain a sufficient volume efficiency even when the rotary valve rotates at a high speed.

[0008]

In order to solve the above-mentioned problems, a reciprocating compressor of the present invention has a cylinder block having a plurality of bores around its axis, and a bearing inserted in a shaft hole of the cylinder block. Formed in the suction chamber communicating with the shaft hole and the outer region of the suction chamber, the piston driven by the swash plate in the crank chamber cooperating with the driving shaft, and directly moving in the bore. In a reciprocating compressor having a housing that has a discharge chamber that closes the end surface of the cylinder block, a communication path that connects the bore and the shaft hole is formed between the bore and the shaft hole. A rotary valve having a suction passage for sequentially connecting the passage of each bore in the suction stroke and the suction chamber is connected to the drive shaft so as to be rotatable synchronously, and the passage of the bore at the end of discharge is connected to the rotary valve. The high-pressure side opening that communicates with the A residual gas bypass passage including a low-pressure side opening communicating with the passage and a communication passage connecting the high-pressure side opening and the low-pressure side opening is formed, and the low-pressure side opening is provided while the communication of the high-pressure side opening is continued. A new structure is adopted in which a branch path for re-communication with an adjacent conduction path is extended.

[0009]

In the reciprocating compressor of the present invention, the rotary valve rotates in synchronization with the drive shaft, so that the refrigerant gas in the suction chamber passes through the suction passage of the rotary valve and the passage of each bore in the suction stroke. Are sequentially sucked into the respective bores, and the suction action of the refrigerant gas is smoothly and stably continued in the respective bores, so that the pressure loss is extremely reduced.

Further, in this compressor, the rotary valve rotates in synchronism with the drive shaft, so that the residual gas in the bore at the end of discharge is recovered by the high pressure side opening, and is transferred to the low pressure side opening via the communication passage. Transferred and bypassed to low pressure side bore by conduit. Thus, the residual gas is less re-expanded during the suction stroke of the bore, and the refrigerant gas in the suction chamber is surely sucked into the bore.

Here, in this compressor, while the high-pressure side opening continues to communicate with the conduction path of the bore at the end of discharge by the rotation of the rotary valve, the low-pressure side opening is formed by the extended branch path. The communication is transferred from the current communication path to the adjacent current path. That is, during this period, the low-pressure side opening first communicates with the low-pressure side bore, is then interrupted, and is re-connected with the conduction path of the adjacent lower-pressure side bore via the branch passage. Therefore, even if the rotation speed of the rotary valve increases,
The gas in the residual gas bypass passage is discharged in two stages on the low pressure side, and the residual gas recovered at the high pressure side opening is sufficiently discharged at the low pressure side opening.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, reference numeral 1 denotes a cylinder block having a central shaft hole 1a penetrating in the axial direction and six bores 1A to 1F. A front housing 2 is joined to one end surface of the cylinder block 1. A rear housing 4 is joined to the other end surface via a ring-shaped valve plate 3. A drive shaft 6 is rotatably supported in a crank chamber 5 in the front housing 2 by being fitted into the front housing 2 and a central shaft hole 1 a of the cylinder block 1. A rotor 7 is fixed on the drive shaft 6, and a long hole 8a is formed at the tip of a support arm 8 extending to the rear surface side of the rotor 7. A pin 8b is slidably fitted in the long hole 8a, and a swash plate 9 is inserted in the pin 8b.
Is tiltably connected.

A sleeve 10 is loosely fitted on the drive shaft 6 adjacent to the rear end of the rotor 7, is constantly biased toward the rotor 7 by a coil spring 11, and is provided on both left and right sides of the sleeve 10. A pivot 10a (only one of which is shown) is fitted into an engagement hole (not shown) of the swash plate 9, and the swash plate 9 is supported so as to be able to swing around the pivot 10a. A swing plate 12 is supported on the rear surface side of the swash plate 9 via a thrust bearing or the like,
Rotation of the oscillating plate 12 is restricted by notches (not shown). Further, six connecting rods 14 are moored to the outer edge of the oscillating plate 12 at equal intervals, and each connecting rod 14 has a bore 1A to.
It is moored with the piston 15 in 1F. Therefore,
The rotary motion of the drive shaft 4 is converted into the back-and-forth swing of the rocking plate 12 by the intervention of the rotor 7 and the swash plate 9, each piston 15 reciprocates in the bores 1A to 1F, and the pressure in the crank chamber 5 changes. The stroke of the piston 15 and the tilt angle of the oscillating plate 12 change according to the pressure difference from the suction pressure. The pressure in the crank chamber 5 is controlled based on the cooling load by a control valve (not shown) mounted in the rear housing 4.

The rear housing 4 is provided with a suction chamber 17 which is open at the rear end face at the center and communicates with the central shaft hole 1a of the cylinder block 1, and a discharge chamber 18 is provided outside the suction chamber 17. Are formed. Valve plate 3
Is a discharge port 3 that communicates with the head of each bore 1A-1F.
a is penetratingly provided, and a retainer 21 is sandwiched via a discharge valve 20 on the discharge chamber 18 side of each discharge port 3a.

Also, as shown in FIG. 2, the cylinder block 1 has radial passages 2A to 2F formed between the bores 1A to 1F and the central shaft hole 1a. As shown in FIG. 1, a cylindrical rotary valve 22 that slides with the central shaft hole 1a is mounted on the tip of the drive shaft 6 extending into the central shaft hole 1a. Are supported on the inner wall of the suction chamber 17 via thrust bearings. The rotary valve 22 is formed with an intake passage 25 that extends in the axial direction from the center of the axial center on the intake chamber 17 side and opens at a predetermined angle on the outer peripheral surface.

A residual gas bypass groove 28 as a residual gas bypass passage is formed in the seal region of the outer peripheral surface of the rotary valve 22 facing the conduction passages 2A to 2F of the bores 1A to 1F in the compression / discharge stroke. There is. The residual gas bypass groove 28 is shown in FIGS. 3 and 4 (in FIGS. 3 and 4, an exploded view of the rotary valve 22 and the central shaft hole 1 a is shown, and is opened in the central shaft hole 1 a as the rotary valve 22 rotates. Conduction path 2A ~
2F shows a state of moving in the direction of the arrow. ), The conducting paths 2A to 2F of the bores 1A to 1F at the end of discharge are shown in FIG.
And a high pressure side groove 28a communicating with the axial direction and a low pressure side groove 2 communicating with the communication passages 2A to 2F of the low pressure side bores 1A to 1F.
8b and a communication groove 28c connecting the high pressure side groove 28a and the low pressure side groove 28b. The low-pressure side groove 28b is divided into two in the axial direction, and a branch path 28d is extended at a predetermined length in the circumferential direction at each end. Further, the low-pressure side groove 28b divided into two parts is shortened in the axial direction, the communication groove 28c is bent midway so as to approach the low-pressure side groove 28b side, and the high-pressure side groove 28a communicates with the communication groove 28c in an arc. ing.

The compressor configured as described above is arranged in the circuit as a vehicle air conditioning refrigeration system and is put to use. When this compressor is operated and the drive shaft 6 shown in FIG. 1 rotates, the swash plate 9 swings while rotating together with the drive shaft 6, and the swing plate 12 is restricted from rotating with respect to the swash plate 9. The oscillating motion is performed only by the above, and thereby the piston 15 reciprocates in the bores 1A to 1F. Then, when the piston 15 starts moving from the top dead center to the bottom dead center in the bores 1A to 1F, the bores 1A to 1F enter the suction stroke. Further, when the piston 15 starts moving from the bottom dead center to the top dead center within the bores 1A to 1F, the bores 1A to 1F enter the compression / discharge stroke.

By rotating the rotary valve 22 in the direction of the arrow in FIG. 2 in synchronism with the drive shaft 6, for example, as shown in FIG.
At the stage shown in, bores 1D to 1F in the suction stroke
The communication passages 2D to 2F communicate with the suction passage 25, and the refrigerant gas in the suction chamber 17 receives the suction passage 25 and the conduction passage 2D.
Through 2F are sequentially inhaled into each bore 1D-1F.
On the other hand, in the bores 1A and 1B during the compression stroke, the passages 2A and 2B of the bores 1A and 1B do not communicate with the suction passage 25, and are closed by the seal region of the rotary valve 22. At this time, bore 1
The pressure inside A and 1B is still lower than the pressure inside the discharge chamber 18, and the discharge valve 20 is closed. In addition, the bore 1C in the discharge stroke
However, the conduction passage 2C does not communicate with the suction passage 25, and is closed by the seal region of the rotary valve 22. But,
At this time, the pressure in the bore 1C becomes higher than the pressure in the discharge chamber 18, and the discharge valve 20 is opened.

In this manner, the bores 1A to 1F sequentially repeat the suction, compression, and discharge strokes via the rotary valve 22 that rotates in synchronization with the reciprocating movement of the piston 15. At this time, the bores 1A to 1F in the suction stroke are communicated with the suction chamber 17 via the communication passages 2A to 2F and the suction passage 25, and the suction action of the refrigerant gas is continued smoothly and stably. Is made extremely small.

In this compressor, for example, at the stage shown in FIG. 3, the communication path 2D of the bore 1D at the end of discharge is communicated with the high pressure side groove 28a, and the low pressure side groove 28b and the bore 1B in the compression stroke are connected. It is in communication. For this reason,
The residual gas in the bore 1D is recovered by the high pressure side groove 28a and transferred to the low pressure side groove 28b via the communication groove 28c,
It is bypassed to the bore 1B during the compression stroke via the conduction path 2B. Thus, in this compressor, re-expansion of the residual gas is small during the suction stroke of the bore 1B, and the refrigerant gas in the suction chamber is reliably sucked into the bore. Further, at this time, since the residual gas is bypassed to the bore 1B during the compression stroke without being depressurized to the suction pressure, a relatively sufficient power efficiency is secured.

After this, when the stage shown in FIG. 4 is reached by the rotation of the rotary valve 22, the high pressure side groove 28a and the bore 1D at the end of the discharge are connected, and the low pressure side groove 28b is extended. As a result, the communication is transferred from the communication path 2B of the bore 1B that is currently in communication with the compression stroke to the communication path 2A of the bore 1A immediately after the end of the adjacent suction stroke. That is, during this period, the low-pressure side groove 28b first communicates with the bore 1B during the compression stroke, and then is temporarily blocked, and the conduction path 2 of the bore 1B immediately after the end of the adjacent suction stroke via the branch passage 28d.
B is connected again. Therefore, even if the number of rotations of the rotary valve increases, the gas in the residual gas bypass groove 28 is 2
The residual gas discharged to the stage and collected in the high pressure side groove 28a is sufficiently discharged in the low pressure side groove 28b. In this way, the residual gas is unlikely to remain in the residual gas bypass groove 28 and is reliably bypassed, so that the suction efficiency is maintained at a high level and the volume efficiency is maintained.

Therefore, in this compressor, the rotary valve 22
Even when rotating at a high speed, it is possible to reliably maintain sufficient volume efficiency. Further, in this compressor, each low-pressure side groove 28b is short in the axial direction, the communication groove 28c is bent, and the high-pressure side groove 28a communicates with the communication groove 28c in an arc. Since the moving distance is short and the residual gas can move smoothly, the bypass can be more effectively performed.

FIG. 5 shows the characteristic curve of this compressor. In FIG. 5, based on a specific bore, for example, the bore 1D shown in FIGS. 3 and 4, the relationship between the rotation angle of the rotary valve 22 and the pressure ratio is shown by a K curve, the bore volume is shown by an L curve, and the suction passage is shown. The communication angle between 25 and the conduction path 2C is indicated by M section. Further, the communication angle between the high-pressure side groove 28a of the residual gas bypass groove 28 and the conduction path 2D is shown as O ₁ section, and the communication angle between the low-pressure side groove 28b or the branch path 28d and the conduction path 2D is shown as O ₂ section. Further, the high pressure side groove 28a of the residual gas bypass groove 28
And the communication angle 2F of the bore 1F with the communication path 2F is shown by Q ₁ section, and the communication angle between the high pressure side groove 28a and the communication path 2E of the bore 1E is shown with Q ₂ section.

As shown in FIG. 5, the bore 1D fixie
If the point 15 passes the top dead center position, O ₁Residual gas
Communication between the high-pressure side groove 28a of the bypass groove 28 and the conduction path 2D is achieved.
Begins. O₁Left over from bore 1D in the first half of the section (hatched area)
Distilled gas is collected and released into the bore 1B,₁After the section
In the half (hatched area), the gas in the residual gas bypass groove 28 is
A. Pressure ratio when released to 1A and past the top dead center position
Is declining favorably. After this, O₂Low-pressure gutter 2 in the section
8b or the branch path 28d communicates with the conduction path 2D, and Q₁section
The high pressure side groove 28a communicates with the conduction path 2F. others
So Q₁Section and O ₂Bore in the overlapping section (diagonal area)
Residual gas is recovered from 1F and discharged into the bore 1D.
Also, Q₂The high-pressure side groove 28a communicates with the conduction path 2E in the section
To do. Therefore, Q₂Section and O₂Overlapping section (diagonal)
Residual gas is recovered from the bore 1E in the line area) and becomes the bore 1D.
Is released. Thus, Q₁Section and O₂Overlapping ward with section
Start of space (diagonal area), Q₂Section and O₂Overlapping ward with section
The pressure ratio rises favorably at the start of the interval (hatched area)
It

FIG. 6 shows the relationship between the bore volume and the bore pressure in this compressor and the compressor of the comparative example. In the compressor of the comparative example, the low pressure side groove 2 of the residual gas bypass groove 28 is used.
8b indicates the bores 1A to 1F and the connecting path 2A immediately after the suction stroke
The angle is set to communicate with each other through ~ 2F. The other structure is the same as that of the embodiment. As shown by the shaded area in FIG. 6, it is understood that the compressor of the example has a lower internal bore pressure at the initial stage of compression and an improved power loss, as compared with the compressor of the comparative example.

Therefore, in this compressor, sufficient volume efficiency can be maintained, sufficient power efficiency can be ensured, and rise in discharge temperature can be suppressed.

[0027]

As described above in detail, since the reciprocating compressor of the present invention has the structure described in the claims, it has a sufficient volume even when the rotary valve rotates at a high speed. The efficiency can be reliably maintained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a compressor according to an embodiment.

FIG. 2 is a cross-sectional view of the compressor of the embodiment.

FIG. 3 is a development view of a rotary valve and a conduction path according to the compressor of the embodiment.

FIG. 4 is a development view of a rotary valve and a conduction path according to the compressor of the embodiment.

FIG. 5 is a graph showing a relationship between a rotation angle and a pressure ratio, etc., relating to the compressor of the embodiment.

FIG. 6 is a graph showing a relationship between a bore volume and a bore pressure in the compressor according to the embodiment.

[Explanation of symbols]

1 ... Cylinder block 1a ... Central shaft hole 1A
~ 1F ... Bore 3 ... Valve plate 4 ... Rear housing 6 ...
Drive shaft 5 ... Crank chamber 9 ... Swash plate 15
... Piston 17 ... Suction chamber 18 ... Discharge chamber 2A
2F ... Conduction path 22 ... Rotating valve 25 ... Suction path 28 ... Residual gas bypass groove (residual gas bypass path) 28a ... High pressure side groove (high pressure side opening) 28b ... Low pressure side groove (low pressure side opening) 28d ... Branch path 28c ... Communication Groove (passage)

Continuation of the front page (72) Inventor, Toru Takeichi, Toyomachi, Kariya city, Aichi prefecture, 1-1-2 Toyota Industries Corp.

Claims (1)

[Claims] 1. A cylinder block having a plurality of bores around an axis, a drive shaft fitted and supported in a shaft hole of the cylinder block, and a swash plate in a crank chamber cooperating with the drive shaft. And a housing that has a suction chamber that communicates with the shaft hole and a discharge chamber that is formed in an outer region of the suction chamber and that closes the end surface of the cylinder block. In the reciprocating compressor, a conduction path is formed between the bore and the shaft hole to connect them, and the drive shaft sequentially communicates the conduction path of each bore in the suction stroke with the suction chamber. A rotary valve having a suction passage is synchronously rotatably coupled to the rotary valve, and a high-pressure side opening communicating with the bore passage at the end of discharge and a low-pressure side bore passage synchronized with the opening. Connect the low pressure side opening communicating with the high pressure side opening and the low pressure side opening. A residual gas bypass passage is formed, and a branch passage is provided in the low-pressure side opening for re-connecting with the adjacent conduction passage while the high-pressure side opening continues to communicate. Reciprocating compressor.